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Hypocatalasia is the deficiency of an enzyme called catalase in red blood cells. The catalase enzyme plays an important role in the cells defense against a type of chemical damage, known as oxidative damage. The disorder is characterized by ulcers and progressive gangrene (tissue death) of the mouth.

Found in

1 in 200 dogs

in our testing

Key Signs

Progressive gangrene in the oral cavity

Age of Onset

0 to 2 yrs

Juvenile onset


Autosomal Recessive

For autosomal recessive disorders, dogs with two copies of the variant are at risk of developing the condition. Dogs with one copy of the variant are considered carriers and are usually not at risk of developing the disorder. However, carriers of some complex variants grouped in this category may be associated with a low risk of developing the disorder. Individuals with one or two copies may pass the disorder-associated variant to their puppies if bred.

Likelihood of the Condition

Moderate likelihood

At risk dogs may show signs of this disease in their lifetime, although some will not develop the condition due to absence of additional risk factors.

What to Do

Here’s how to care for a dog with Hypocatalasia

Partner with your veterinarian to make a plan regarding your dog’s well-being, including any insights provided through genetic testing. If your pet is at risk or is showing signs of this disorder, then the first step is to speak with your veterinarian.

For Veterinarians

Here’s what a vet needs to know about Hypocatalasia

The clinical signs of hypocatalasia in dogs have not been described properly in the literature but include progressive gangrene in the oral cavity. In the human condition, the severity of signs can vary remarkably. The erythrocytes of affected dogs show no signs of catalase activity.

Treatment is pain management, supportive care, and symptomatic depending on the severity of the dog's clinical signs.

For Breeders

Planning to breed a dog with this genetic variant?

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

Although this disease is poorly discribed, our understanding is that this disease is autosomal recessively inherited, meaning that two copies of the mutation are needed for disease signs to occur. Avoiding use of carrier dogs for breeding purposes will ensure dogs in the resulting litter are clear of this mutation Breeding a carrier dog with one copy of the Hypocatalasia mutation with a clear dog with no copies of the Hypocatalasia mutation, will result in a litter containing half carriers and half clear dogs. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the Hypocatalasia mutation could develop due to a different genetic or clinical cause.

Technical Details

Gene CAT
Variant G>A
Chromosome 18
Coordinate 33,397,548

All coordinates reference CanFam3.1

References & Credit

Credit to our scientific colleagues:

Nakamura, K., Watanabe, M., Takanaka, K., Sasaki, Y., & Ikeda, T. (2000). cDNA cloning of mutant catalase in acatalasemic beagle dog: Single nucleotide substitution leading to thermal-instability and enhanced proteolysis of mutant enzyme. International Journal of Biochemistry and Cell Biology, 32(11–12), 1183–1193. View the article